Many devices and computer-based services today rely upon communication systems to transfer necessary information between one another. The communication systems, in turn, are comprised of numerous independent communication networks, including wireline and wireless networks, all of which need to cooperate with one another in order to form a large, interconnected, ubiquitous communication system.
For example, the Internet, as well as most commercial networks, are configured according to a TCP/IP architectural model that utilizes a TCP/IP protocol suite. The TCP/IP protocol suite is oftentimes thought of as a collection of layers, each of which is responsible for a certain well-defined set of responsibilities so that together the suite of protocols acts as a whole. According to one embodiment, the TCP/IP protocol suite includes an application layer, a transport layer using a Transmission Control Protocol (TCP), an Internet layer using an Internet Protocol (IP), a network layer, and a physical layer.
Another example of a protocol suite is the OSI model, which was established after the TCP/IP protocol suite and differs from that suite in several respects. For instance, the OSI model includes seven layers (Application, Presentation, Session, Transport, Network, Data Link, and Physical layers), where the TCP/IP protocol suite only includes five layers. When making comparisons between the two protocol suites, sometimes the Presentation and Session layers of the OSI model are included within the Application layer so that they form a single combined layer.
It should be appreciated that while the TCP/IP and OSI protocol suites mentioned above make up a large portion of the communications systems currently in use, additional protocol suites, such as proprietary protocol suites, can also be used to configure a communications system.